When ldap is opened, I config the kylin.properties, and give wkhGroup the admin permission.
then I create a new user named 'wkh' whose group is 'wkhGroup', then I use 'wkh' to login in, which is normal.
But when I use 'WKH' to login in, the page does not respond.
I analyze the backgroud code, and find the function of 'org.apache.kylin.rest.security.LDAPAuthoritiesPopulator.getGroupMembershipRoles(String, String)' has problem.
When userDn is "uid=wkh,ou=People,ou=defaultCluster,dc=zdh,dc=com" and username is "WKH", then authorities will be empty Set by the follow code:
So I have added 'getAdditionalRoles' function to get the authorities again.
I have test the patch, please review, thanks!